Stopper plate mounting for pushbutton switch

ABSTRACT

A pushbutton switch comprises a pushrod having communicating vertical and longitudinal channels, the stopper plate against which the biasing spring is adapted to operate having downwardly extending arms with inwardly extending parts, the inwardly extending parts being passable through the vertical channels and then being movable along the longitudinal channels to the ends thereof under the influence of the biasing spring.

O Unlted States Patent 1 1 3,591,750

[72] Inventor 'MasaoOhkita [56] References Cited Java" UNITED STATESPATENTS Q12; g 6 m0 2,156,946 5/1939 ClOSSOl'I e161 200/169 PB [45]Patented luly'6 2,433,710 12/1947 Schleicher ..200/166 BC (X) 2,524,21510/1950 Wegehoft.... 200/172 A 2,811,617 10/1957 Townsend 200/166 13c Y3,172,985 3/1965 De Smidt 200/172A Pmmy 1969 5 244 847 4/1966 E 1200/172 R x [33] {Japan rpe 31 44/112,695 Primary Examiner-H. 0. JonesAttorney-James and Franklin ABSTRACT: A pushbutton switch comprises apushrod hav- [54] S :EZ PLATE MOUNTING FOR PUSHBUTTON ing communicatingvertical and longitudinal channels, the WI D stopper plate against whichthe biasing spring is adapted to 8 Chums 6 raw'ng operate havingdownwardly extending anns with inwardly ex- [52] U.S.Cl. ZOO/172Rtending parts, the inwardly extending parts being passable [51] lnt.ClH0lh through the vertical channels and then being movable along Field ofSearch 200/172, the longitudinal channels to the ends thereof under thein- 166 BC, 169 PB, 159 R fluence of the biasing spring.

STOPPER PLATE MOUNTING FOR PUSIIBUTTON SWITCH This invention relates toa pushbutton switch and more particularly to improvements in themounting of the stopper plate on the pushrod of that switch.

The conventional pushbutton switch has a pushrod which is adapted to bemoved in and out to actuate the switch, a biasing spring beingoperatively connected to that pushrod so as normally to urge it to itsoutward position. That spring acts on the pushrod by means of a stopperplate which is mounted on the pushrod. In the past the mounting of thestopper plate on the pushrod has involved a resilient action during thetime that the stopper plate and pushrod are being assembled together.The thus-necessitated resiliency of the stopper plate has led toexcessive cost, since when the stopper plate is made of resilientmaterial it must be more expensive than if it were made of some rigidmaterial. In addition, the resiliency of the material of which thestopper plate was made was in itself disadvantageous, since it presenteda somewhat unsteady backing for the biasing spring. Moreover, the actualmounting of the stopper plate on the pushrod required the application ofappreciable force onthe stopper plate, and this gave. rise to distortionof parts during the assembly operation.

It is the prime object of the present invention to eliminate thesedisadvantages by providing a rigid stopper plate which can readily bemounted on the pushrod and which, when thus mounted, will provide areliable and effective element for engagement with the biasing spring.

It is a further object of the present invention to provide a pushbuttonswitch which has a reliable and relatively inexpensive construction.

In order to perform the above objects, the pushrod of the switch isformed with substantially vertical side channels and with substantiallylongitudinally extending channels communicating therewith. The stopperplate is provided with depending arms with inwardly extending parts,those parts being vertically movable through the vertical channels tothe longitudinal channels and then being slidable along the longitudinalchannels to the end walls of those latter channels. The biasing springwhich is compressed between the switch body and the stopper plate properurges the stopper plate to the position in which the inwardly extendingparts reach and are. pressed against the ends of the longitudinalchannels. Thus assembly of the parts is easily accomplished, noparticular force need be exerted on the parts when they are assembled,the stopper plate is rigid and therefore provides a very firm andeffective backing for the biasing spring, and the stopper plate may bemade of relatively inexpensive material because it can be rigid.

To the accomplishment of the'above, and to such other objects as mayhereinafter appear, the present invention relates to the mounting of astopper plate on the pushrod of a pushbutton switch, as defined in theappended claims and as described in this specification, taken togetherwith the accompanying drawings, in which:

FIG. 1A is a three-quarter perspective view of a portion of a pushbuttonswitch pushrod and the stopper plate adapted to be associated therewithaccording to the prior art;

FIG. 1B is a cross-sectional view of the assembled prior art structureof FIG. 1A, taken along the line 18-18 of FIG. 1A;

FIG. 2 is a three-quarter perspective view of a pushbutton switch body,pushrod, stopper plate and biasing spring assembly in accordance withthe present invention;

FIG. 3A is a cross-sectional view taken along the line 3A-3A of FIG. 2;

FIG. 3B is a cross-sectional view taken along the line 3B-3B of FIG. 2;and

FIG. 4 is an exploded view of the assembly of FIG. 2, showing thestopper plate in position ready to be assembled and mounted onto thepushrod.

A pushbutton switch of the type here under discussion comprises a bodygenerally designated A within which the switching elements and contactsare received. The internal structure of the body A, and the electricaland mechanical arrangement therein, form no particular part of thepresent invention, and therefore no details thereof are shown. A pushrodgenerally designated 8 extends from the body A and is adapted to bemoved into and out from that body, thereby selectively to actuate theparts within the body so as to cause one type or another of electricalconnection to be effectuated. The pushrod B is normally urged outwardlyby a biasing spring generally designated C, that spring beingcompressedbetween -the body A and a stopper plate generally designated D which ismounted on the pushrod B.

FIGS. 1A and lB illustrate the established prior art method of mountingthe stopper plate D on the pushrod B. In accordance with the 'prior artthe pushrod B is provided with a pair of vertically extending channels 2extending from the top wall 4 to the bottom wall 6 thereof. The stopperplate D is provided with an upper body portion 8 and depending arms 10,the space between the arms being substantially equal to the width of thepushrod B between the vertical channels 2 thereof. At the lower ends ofthe depending arms 10 are inwardly extending projections 12 which, asmay best be seen from FIG. 1B, are adapted to snap beneath the lowersurface 6 of the pushrod B. Inorder for this to occur the stopper plateD must be sufficiently resilient so that the arms 10 may spread apart asthe stopper plate D is pushed down onto the pushrod B from its positionshown in FIG. 1A to its position shown in FIG. 1B. This necessaryresiliencyof the stopper plate Dv requires that the plate be formed of arelatively expensive material. Moreover, it is not feasible to make onlythe arms 10 resilient, and consequently all of the plate D is resilient.As-a result, when the biasing spring C engages with the stopper plate D,the stopper plate D is somewhat distorted or resiliently bent by theaction of the biasing spring C, thus giving rise to unreliability ofoperation.

In order to eliminate these disadvantages, and as illustrated in FIGS.2-4, the pushrod B of the present invention is provided withsubstantially vertically extending channels 2 which, at their lowerends, communicate with substantially longitudinally extending channels14 in the pushrod B, those longitu:

dinally extending channels 14 extending from the lower ends of thevertical channels 2 in a direction away from the switch body A, there toterminate in end walls 16.

The stopper plate I) .comprises a body portion 18 from which arms 20depend, those arms having inwardly extending parts. 22. at their lowerends. In contradistinction to the inwardly extending parts 12 of theprior art embodiment illustrated in FIGS. 1A and 1B, the inwardlyextending parts 22 of the stopper. plate of the present inventionterminate in facing substantially vertical surfaces 24 which are ofappreciable height and which are substantially vertical, these surfaces24 being adapted to cooperate with the sidewalls 26 of thelongitudinally extending channels 14. The spacing between the surfaces24 is thus seen to be approximately the same as the width of themounting portion of the pushrod B between thevertically extendingchannels 2, that being designated by the arrows 28 in FIG. 4. Thespacing between the arms 20 above the inwardly extending parts 22 isapproximately equal to the overall width of the mounting portion of thepushrod B, as-indicated by the arrows 30 in FIG. 4. The vertical spacingbetween the body portion 18 of the stopper plate D and the inwardlyextending parts 22 is substantially equal to the spacing between theupper surface of the pushrodB and the upper surfaces 32 of thelongitudinally extending channels 14.

The biasing spring C is preferably helical in nature and surrounds thepushrod B. One end thereof engages the front face 34 of the switch body-A, and the other end thereof engages portions of the stopper plate Dwhich extend out beyond-the pushrod B. As will be seen from thedescription of the assembly of the parts which follows, the stopperplate D may be made of rigid material, and preferably is so constructed.

Hence, it provides a very effective backing or stop for the biasingspring C, and reliably transmits the biasing force of that spring to thepushrod B.

To assemble the parts the biasing spring C is first placed over thepushrod B, moved into engagement with the face 34 of the switch body A,and compressed until it has moved to the right (as viewed in FIG. 4)beyond the vertically extending channels 2 in the pushrod B. Then, whilethe biasing spring C is retained in that compressed condition, thestopper plate D is moved downwardly from its position shown in FIG. 4,the inwardly extending parts 22 thereof entering into and sliding downthrough the vertical channels 2, but without any distortion of thestopper plate D. When the stopper plate D has moved down as far as itcan go, with its body portion 18 resting on the upper surface of thepushrod B, the inwardly extending parts 22 will be in registration withthe right-hand ends of the longitudinally extending channels 14. At thispoint the biasing spring C may be released. [twill tend to expand andwill engage the stopper plate D, pushing the latter to the left asviewed in FIG. 4. Under the action of the biasing spring C the stopperplate D will move to the left, its inwardly extending parts 22 slidingalong the longitudinal channels 14 and its arm 20 sliding along the sidesurfaces of the pushrod B, until the inwardly extending parts 22 reachthe end walls 16 of the longitudinal channels 14. At that point thespring-urged movement of the stopper plate D relative to the pushrod Bwill cease, and thereafter the resilient force of the biasing spring Cwill be exerted rigidly through the stopper plate D to the pushrod B,retaining that pushrod B in its outer position until it is manuallypushed inwardly. The surfaces 24 of the inwardly extending parts 22 onthe stopper plate D essentially mate with and ride along the surfaces 26of the channels 14, thus steadying and guiding the stopper plate D onthe pushrod B and preventing relative rotation of those parts.

From the above it will be seen that the stopper plate D of the presentinvention need not be, and preferably is not, resilient, and hence itmay be manufactured at a lower cost than has previously been thoughtfeasible. Moreover, the assembly of the parts is greatly facilitated, noforce need be ex erted in the course of the assembly, and consequentlydamage to the parts and subsequent rejection of the assemblies isminimized.

While but a single embodiment of the present invention has been herespecifically disclosed, it will be apparent that many variations may bemade therein, all within the scope of the invention as defined in thefollowing claims.

lclaimz.

1. A pushbutton switch comprising a body, a pushrod movable into and outfrom said body, said pushrod having a mounting portion comprising anupper section having a predetermined width and a lower section having alesser width and defining with said upper section substantiallylongitudinally extending channels terminating in end walls at those endsof said longitudinal channels directed away from said body, saidmounting portion having substantially vertical side channels open at thetop and communicating with said longitudinally extendingchannelsrespectively at those ends of said longitumounted on and extending fromsaid pushrod and having depending arms with inwardly extending parts,said arms being spaced from one another by a distance no less than saidpredetermined width, said parts being spaced from one another by adistance less than said predetermined width and no less than said lesserwidth, said vertical side channels being of a size to accommodate saidinwardly extending parts, and a spring active between said body and saidstopper plate and effective to urge said stopper plate away from saidbody, said inwardly extending parts then being urged into engagementwith said end walls of said longitudinal channels.

2. The switch of claim 1, in which said stopper plate is essentiallyrigid.

3.'The switch of claim 2, in which the opposing portions of saidinwardly extendin parts are defined by surfaces of appreciable height,said ongitudinally extending channels having walls of appreciable heightagainst which said portion surfaces are engaged.

4. The switch of claim 1, in which the opposing portions of saidinwardly extending parts are defined by surfaces of appreciable height,said longitudinally extending channels having walls of appreciableheight against which said portion surfaces are engaged.

5. A pushbutton switch comprising a body, a pushrod movable into and outfrom said body, said pushrod having a pair of opposed open-toppedvertically extending channels in opposite sides thereof, and a pair oflongitudinal channels communicating with said vertical channelsrespectively at their lower ends, extending therefrom in a directionaway from said body, and terminating in end walls, a stopper platecomprising a body portion adapted to extend from said pushrod, a pair ofarms depending from said body portion and spaced from one another by adistance substantially equal to the width of said rod, and a pair ofinwardly extending parts on said arms spaced below said body, said partsbeing passable through said vertical channels and slidable along saidlongitudinal channels while said body portion of said stopper plate isabove said pushrod, and a spring active between said body and saidstopper plate and effective to urge said stopper plate away from saidbody and said inwardly extending parts into engagement with said endwalls of said longitudinal channels.

6. The switch of claim 5, in which said stopper plate is essentiallyrigid.

7. The switch of claim 6, in which the opposing portions of saidinwardly extending parts are defined by surfaces of appreciable height,said longitudinally extending channels having walls of appreciableheightagainst which said portion surfaces are engaged.

8. The switch of claim 5, in which the opposing portions of saidinwardly extending parts are defined by surfaces of appreciable height,said longitudinally extending channels having walls of appreciableheight against which said portion surfaces are engaged.

1. A pushbutton switch comprising a body, a pushrod movable into and outfrom said body, said pushrod having a mounting portion comprising anupper section having a predetermined width and a lower section having alesser width and defining with said upper section substantiallylongitudinally extending channels terminating in end walls at those endsof said longitudinal channels directed away from said body, saidmounting portion having substantially vertical side channels open at thetop and communicating with said longitudinally extending channelsrespectively at those ends of said longitudinal channels directed towardsaid body, a stopper plate mounted on and extending from said pushrodand having depending arms with inwardly extending parts, said arms beingspaced from one another by a distance no less than said predeterminedwidth, said parts being spaced from one another by a distance less thansaid predetermined width and no less than said lesser width, saidvertical side channels being of a size to accommodate said inwardlyextending parts, and a spring active between said body and said stopperplate and effective to urge said stopper plate away from said body, saidinwardly extending parts then being urged into engagement with said endwalls of said longitudinal channels.
 2. The switch of claim 1, in whichsaid stopper plate is essentially rigid.
 3. The switch of claim 2, inwhich the opposing portions of said inwardly extending parts are definedby surfaces of appreciable height, said longitudinally extendingchannels having walls of appreciable height against which said portionsurfaces are engaged.
 4. The switch of claim 1, in which the opposingportions of said inwardly extending parts are defined by surfaces ofappreciable height, said longitudinally extending channels having wallsof appreciable height against which said portion surfaces are engaged.5. A pushbutton switch comprising a body, a pushrod movable into and outfrom said body, said pushrod having a pair of opposed open-toppedvertically extending channels in opposite sides thereof, and a pair oflongitudinal channels communicating with said vertical channelsrespectively at their lower ends, extending therefrom in a directionaway from said body, and terminating in end walls, a stopper platecomprising a body portion adapted to extend from said pushrod, a pair ofarms depending from said body portion and spaced from one another by adistance substantially equal to the width of said rod, and a pair ofinwardly extending parts on said arms spaced below said body, said partsbeing passable through said vertical channels and slidable along saidlongitudinal channels while said body portion of said stopper plate isabove said pushrod, and a spring active between said body and saidstopper plate and effective to urge said stopper plate away from saidbody and said inwardly extending parts into engagement with said endwalls of said longitudinal channels.
 6. The switch of claim 5, in whichsaid stopper plate is essentially rigid.
 7. The switch of claim 6, inwhich the opposing portions of said inwardly extending parts are definedby surfaces of appreciable height, said longitudinally extendingchannels having walls of appreciable height against which said portionsurfaces are engaged.
 8. The switch of claim 5, in which the opposingportions of said inwardly extending parts are defined by surfaces ofappreciable height, said longitudinally extending channels having wallsof appreciable height against which said portion surfaces are engaged.